1. Field of the Invention
The present invention relates to a container storage facility comprising a vehicle for transporting a container for holding at least one substrate, and a container storage section for storing the container transported by the vehicle.
2. Description of the Related Art
In the container storage facilities described above, transporting means including a vehicle is provided for transporting containers among a plurality of processing devices for processing substrates which have been, for example, taken out of containers. Container storage sections are provided, for example, to temporarily store containers before they are transported to the processing device, or to store the containers that have been processed by the processing device and that are destined to be moved out of the facility. Each container storage sections is configured to be capable of transferring (i.e. delivering and receiving) a container to and from the transporting means.
In this container storage facility, a storage shelf is conventionally provided that includes a plurality of container storage units which are each capable of storing a container and which are arranged in the vertical direction and the horizontal direction. There are some conventional facilities in which this storage shelf function as a container storage section. (See for example, Japanese Publication Of Application No. 2001-338971.) In the facility described in this publication, the storage shelf is configured to be a stationary type installed on the floor surface, and its transporting means is configured to transfer containers to and from the plurality of the fixed container storage units.
And there is also another type of container storage facility in which a plurality of container storage sections are arranged along the travel path of the transporting means. (See, for example, Japanese Publication Of Application No. 2009-253162.) In the facility described in this publication, each container storage section includes a fixed frame immovably or fixedly provided and a container support provided for movement with respect to the fixed frame between a storage position for storing a container and a transfer position for transferring a container to and from the transporting means. When transferring a container between the transporting means and the container storage section, the container support located in the storage position is moved from the storage position to the transfer position. The transporting means then transfers the container to or from the container support located in the transfer position. When the transfer is completed, the container support is returned from the transfer position to the storage position.
As described above, as the container storage section, there is the container storage section of a fixed type disclosed in Japanese Publication Of Application No. 2001-338971 as well as the container storage section which can be moved between the storage position and transfer position as disclosed in Japanese Publication Of Application No. 2009-253162. In a conventional container storage facility, both the container storage section of the fixed type and the container storage section which can be moved between the storage position and the transfer position are provided as its container storage sections. The transporting means can move to and from the container storage section of the fixed type and is configured to transfer a container to and from the container storage section of the fixed type. The transporting means can also move to and from the container storage section which can be moved between the storage position and the transfer position and is configured to transfer a container to or from the container storage section that had been moved from the storage position to the transfer position.
The space within the container is filled with inert gas, such as nitrogen or argon, or with CDA (Clean Dry Air) in order to prevent an oxide film due to oxygen in the air from forming on the surfaces of the substrates (for example, semiconductor wafer) in the container. To this end, in the facility discussed in the Japanese Publication Of Application No. 2001-338971, gas supply means is provided for supplying inert gas to the container stored in a container storage section of the fixed type. A supply port for supplying the nitrogen gas to the interior of the container and an exhaust port for releasing the air containing oxygen from the interior of the container are provided to the container. The gas supply means supplies the inert gas through the supply port of the container stored in the storage shelf, replaces the internal air, and fills the container with the inert gas.
Thus, the container storage section has been contemplated as a location at which inert gas is supplied to the container. However, while gas supply means is provided to the container storage section of the fixed type as described in Japanese Publication Of Application No. 2001-338971, no gas supply means is provided to the container storage section which can be moved between the storage position and the transfer position as described in Japanese Publication Of Application No. 2009-253162, making it impossible to fill the container with inert gas at such storage section. Thus, the container that needs to be filled with inert gas is conventionally transported by the transporting means, not to the container storage section which can be moved between the storage position and the transfer position, but to the container storage section of the fixed type which can supply inert gas to the container to fill the space within the container with inert gas.
However, since it is necessary to secure installation space on the floor surface for other devices such as the processing devices that actually contribute directly to production of the substrates, it is difficult to install a plurality of storage shelves close to the processing devices. Therefore, in a facility where the container storage sections of the fixed type are the only locations at which inert gas is supplied to the containers, the distance, which the transporting means has to cover to transport the containers to container storage sections for storing the containers after being processed by processing devices, becomes long, using up transporting capacity of the transporting means, which leads to a problem of not using the transporting capacity of the transporting means effectively.
And, the container storage section which can be moved between the storage position and the transfer position requires a smaller installation space compared with the container storage section of the fixed type, and can be installed in the ceiling where comparatively large space is available. Accordingly, it is also contemplated to provide facilities recently in which a large number of container storage sections which can be moved between the storage position and the transfer position are installed in lieu of the container storage section of the fixed type, or without any container storage section of the fixed type. In such facility, since there would be a smaller number of the container storage sections of the fixed type which can supply inert gas to the containers, it is desirable to have the container storage sections which can be moved between the storage position and the transfer position and that can supply inert gas to the containers.
To this end, it would be possible to supply inert gas to the container by providing the container storage section which can be moved between the storage position and the transfer position with a gas supply line that can be extended and retracted with the movement of the container support when it is moved between the transfer position and the storage position. However, in this case, since the gas supply line would be extended and retracted every time the container support is moved between the transfer position and the storage position, the gas supply line would deteriorate prematurely. And, when the gas supply line is extended and retracted, dust is generated, which is not desirable in ensuring high quality of the substrates.